Powered roller conveyor systems are used in the material handling system to convey articles such as products in totes or cartons through a material handling system. A drive belt or chain can be used to turn rollers that provide the support surface for the articles. One generally-known accumulation and transportation conveyor uses a drive belt that longitudinally underlies the roller that are oriented transverse to the longitudinal axis of the conveyor. This generally-known belt-drive roller conveyor has an elongate transverse cross section with a thin vertical cross section. Thus, the section of conveyor served by such a particular belt is necessarily straight or nearly straight. At each end of the section, the upper portion of the belt by a pulley having a horizontal, transverse axis guiding the remainder of a belt loop beneath the portion that drives the rollers. The belt can have advantages of being relatively quiet as compared to chains.
Another generally-known powered roller conveyor incorporates a drive chain that is topped by a drive pad that contacts the undersurface of the live rollers. This chain-driven pad is relatively narrow in horizontal cross section as installed down a longitudinal axis of the conveyor. Being narrow, the chain-driven pad can be horizontally turned at each end of a section of conveyor. This horizontal return loop enables curving the section of conveyor to the right or left as required rather than having to be essentially straight. Although providing design flexibility, the drive chain can create more noise than a belt implementation.